Structure and corrosion resistance of Al–Cu–Fe alloys

The microstructure and electrochemical properties of Al–Cu–Fe alloys with the atomic compositions of Al65Cu20Fe15, Al78Cu7Fe15 and Al80Cu5Fe14Si1 have been studied. The alloys were produced by induction melting of pure elements with copper mold casting. The microstructure of the alloys was analyzed by X-ray diffraction and high-resolution transmission electron microscopy. The formation of quasicrystalline phases in the Al–Cu–Fe alloys was confirmed. The presence of intermetallic phases was observed in the alloys after crystallization in a form of ingots and plates. The electrochemical measurements were conducted in 3.5% NaCl solution. The electronic structure of the alloys was determined by X-ray photoelectron spectroscopy. The post corrosion surface of the samples was checked using a scanning electron microscope equipped with the energydispersive X-ray detector. It was observed that the Al65Cu20Fe15 alloy had the highest corrosion resistance. The improved corrosion resistance parameters were noted for the plate samples rather than those in the as-cast state. And the hardness of the Al65Cu20Fe15 alloy was significantly higher than the other alloy samples

Surface modification of biomedical MgCa4.5 and MgCa4.5Gd0.5 alloys by micro-arc oxidation

The aim of this work was to characterize the structure and corrosion properties of the MgCa4.5(Gd0.5) alloys surface treated by the micro-arc oxidation (MAO) process. The MgCa4.5 and MgCa4.5Gd0.5 alloy samples were processed by MAO in an electrolyte composed of NaOH (10 g/dm3), NaF (10 g/dm3), NaH2PO4 (5 g/dm3), Na2SiO2·5H2O (10 g/dm3) and water. Two different voltages (120 V and 140 V) were used in the MAO process. The alloys protected by an oxide layer formed in the MAO were then the subject of corrosion resistance tests in an environment simulating the human body (Ringer’s solution). After the experiments, the resulting samples were investigated with using SEM, XPS and EDS techniques. The addition of Gd affected the fragmentation of the coating structure, thereby increasing the specific surface; higher voltages during the MAO process increased the number and size of surface pores. Corrosion tests showed that the MgCa4.5Gd0.5 alloys were characterized by low polarization resistances and high corrosion current densities. The studies indicated the disadvantageous influence of gadolinium on the corrosion resistance of MgCa4.5 alloys. The immersion tests confirmed lower corrosion resistance of MgCa4.5Gd0.5 alloys compared to the referenced MgCa4.5 ones. The MgCa4.5 alloy with the MAO coating established at voltage 140 V demonstrated the best anticorrosion properties

Участие в туризме и двигательной рекреации пожилых людей-жителей Жешува

Cel artykułu: ukazanie uczestnictwa osób starszych w turystyce i rekreacji ruchowej oraz motywacje mające wpływ na ich zachowania w wolnym czasie. W tym celu przebadano seniorów w Uniwersytecie Trzeciego Wieku oraz w Klubie Seniora. Rodzaj wykorzystanej metodologii badawczej: metodologia badawcza opierała się na zastosowaniu metody sondażu diagnostycznego przy wykorzystaniu narzędzia badawczego, jakim jest kwestionariusz ankiety. Główne wyniki badań/analiz: wyniki badań dotyczą uczestnictwa osób starszych w turystyce i rekreacji, na przykładzie seniorów, mieszkańców Rzeszowa. Z przeprowadzonych badań wynika, że emerytów do uprawiania rekreacji ruchowej najczęściej motywuje chęć odpoczynku w kontakcie z przyrodą oraz poprawa zdrowia. Przez ruch odczuwają oni radość, odprężenie i spokój, a także, co bardzo istotne, zależy im na efektywnym spędzaniu wolnego czasu i regeneracji sił psychofizycznych. Implikacje praktyczne: analizując wyniki badań można wywnioskować, jakie formy aktywności ruchowej i wyjazdów turystycznych preferują seniorzy z Rzeszowa. Dzięki temu władze miasta mają możliwość dopasowania infrastruktury turystycznej i rekreacyjnej do potrzeb i możliwości osób starszych, aktywnie spędzających swój czas wolny, którego mają dostatecznie dużo. Implikacje społeczne: dzięki uczestnictwu w turystyce i rekreacji ruchowej seniorzy mogą aktywnie spędzać czas wolny. Uprawianie turystyki i rekreacji przyczynia się również do uczestnictwa seniorów w życiu społeczeństwa, a przez to pozytywnie wpływa na ich samopoczucie psychofizyczne, a co się z tym wiąże – przyczynia się do wzrostu jakości ich życia. Kategoria artykułu: badawczyAim of the article: to show participation of elderly people in tourism and physical recreation as well as the motivations affecting their behaviour at one’s leisure. For this purpose, elderly people at the Third Age University and in the Senior’s Club were surveyed. Type of the research methodology used: the research methodology was based on the application of the method of diagnostic survey with the use of a questionnaire as the research tool. Main findings of research/analyses: the research findings concern the participation of the elderly in tourism and recreation, on the example of senior residents of the city of Rzeszów. The carried out surveys show that pensioners are most often motivated to exercise physical recreation by the desire to rest in the contact with nature and to improve one’s health. Through movement they feel joy, relax and peace of mind as well as, what is very important, they matter an effective spending their free time and regeneration of their psychophysical strengths. Practical implications: analysing the research findings one may conclude which forms of physical activity and tourist trips are preferred by seniors from Rzeszów. Owing to that, the urban authorities have an opportunity to match the tourism and recreational infrastructure to the needs and abilities of elderly people spending their free time which they have sufficiently much. Social implications: owing to their participation in tourism and physical recreation, seniors may spend their free time actively. Exercising tourism and recreation also contributes to the seniors’ participation in the society’s life what positively affects their psychophysical frame of mind and, what is related thereto, contributes to an increase in the quality of their life.Цель статьи: указать участие пожилых людей в туризме и двигательной рекреации, а также мотивировки, влияющие на их поведение на досуге. Для этого обследовали пожилых людей в Университете третьего возраста и в Клубе для пожилых людей. Вид использованной исследовательской методологии: исследовательская методология основывалась на применении метода диагностического зондажа с использованием исследовательского инструмента, каким является вопросник анкеты. Основные результаты изучения/анализов: результаты изучения касаются участия пожилых людей в туризме и рекреации на примере лиц пожилого возраста, жителей Жешува. Из проведенного изучения вытекает, что пенсионеров к занятиям двигательной рекреацией чаще всего мотивирует желание отдохнуть наедине с природой и улучшить состояние здоровья. Благодаря движению они чувствуют радость, облегчение и покой, а также, что весьма важно, заботятся об эффективном проведении досуга и восстановлении психофизических сил. Практические импликации: анализируя результаты изучения, можно прийти к выводу, какие формы двигательной активности и турпоездок предпочитают пожилые люди из Жешува. Благодаря этому городские власти могут приспособить туристскую и рекреационную инфраструктуру к потребностям и возможностям пожилых лиц, активно проводящих свой досуг, которого у них достаточно большой объем. Социальные импликации: благодаря участию в туризме и двигательной рекреации пожилые лица могут активно заниматься на досуге. Занятие туризмом и рекреацией способствует тоже участию пожилых людей в жизни общества и, благодаря этому, оно положительно влияет на их психофизическое самочувствие и, что связано с этим, способствует повышению качества их жизни

Plasma microRNA-320a as a Potential Biomarker of Physiological Changes during Training in Professional Volleyball Players

A deeper insight into the mechanisms responsible for athlete performance that may serve as specific and detailed training indicators is still desired, because conventionally used biomarkers provide limited information about the adaptive processes that occur during exercise. The objective of our study was to assess insulin-like growth factor 1 receptors (IGF1R) gene expression and evaluate plasma concentration of selected microRNAs (miRNAs) during a 10-week training period (sampling times: week 1, 4, 7, and 10) in a group of 12 professional female volleyball players. Circulating miRNAs (miR-223, miR-320a, and miR-486) with established concentration in plasma and documented association with the IGF1 signaling pathway, which is involved in muscle development and recovery, were tested. The levels of analyzed miRNAs, tested by one-way ANOVA, were significantly different between four training periods during a 10-week training cycle (miR-223 p < 0.0001, miR-320a p = 0.00021, miR-486 p = 0.0037, respectively). The levels of IGF1R also appeared to be different (p = 0.00092), and their expression showed a trend to increase between the first and third periods. In the fourth period, the expression decreased, although it was higher compared with the baseline. Correlations between concentration levels of miR-223 and miR-320a (rs = 0.54, p < 0.001), as well as between miR-320a and miR-486 (rs = 0.73, p < 0.001) were also found. In the fourth period, a negative correlation between miR-223 plasma level and leucocyte IGF1R expression was found (rs = −0.63, p = 0.028). Multiple linear regression analysis showed that miR-320a (p = 0.024) and creatine kinase (p = 0.028) had the greatest impact on the expression levels of the IGF1R gene. Future studies are required to define whether these miRNAs, especially miR-320a, as well as IGF1R expression could be useful biomarkers of physiological changes during exercise and to discover their detailed biological roles in mode-specific exercise training adaptations of professional athletes

Association Analysis of Polymorphic Variants of the BDNF Gene in Athletes

As BDNF is one of the group of neurotrophins highly influencing the processes happening in the brain, such as the processes of learning and personality creation, we decided to look closer at its genetic variations in association with the personality of a group of athletes and their controls. The study group consisted of 305 volunteers: martial arts athletes (n = 153; mean age = 24.06) and healthy non-athletes as controls (n = 152; mean age = 22.23). Thirty-eight percent of the martial arts group achieved the championship level. Both the martial arts and control subjects were examined using the NEO Five-Factor Personality Inventory (NEO-FFI) and the State-Trait Anxiety Inventory (STAI) scales. The results of the NEO-FFI and STAI inventories were given as sten scores. The conversion of the raw score to the sten scale was performed according to Polish norms for adults. Genomic DNA was extracted from blood leukocytes and then genotyped using a PCR method for the following polymorphisms: BDNF rs10767664 and BDNF rs2030323. We observed statistical significance for both polymorphisms when comparing martial arts athletes with the control group in relation to the conscientiousness and extraversion scales. However, since few extant articles consider this association, our results still require further analysis, probably by considering a larger group